The Internet and many on-line information services provide electronic mail (e-mail), conferencing and chat services, and the ability to access remote computers for sending and retrieving files. E-mail, perhaps the most widely used of Internet and on-line service applications, has an (often desirable) inherent "off-line" time delay characteristic.
Internet Relay Chat (IRC) or, simply "chat" provides informal communications among users of data network facilities. Chat allows two or more users to converse by exchanging text messages, typically through a "channel" or virtual "chat room" maintained on one or more chat servers and accessed via an on-line service or using general purpose chat "client" software executing at a user terminal, workstation or personal computer. Only chat "participants" connected (typically through a telephone line modem) to the on-line service or other chat environment provided by one or more chat servers, can take part in the chat. Chat room "conversations" are displayed as text in a chat room window on a participant's display screen, usually accompanied by a list of chat participants. The text displayed at a participant's terminal usually includes a history of the conversation from the time that the viewing participant joined the chat room. Entering particular chat rooms is typically effected using a list or menu of currently available chat rooms. Exiting a chat room is usually as simple as closing the chat window. Extensions of the basic chat model of communications permit use of voice (or other audio), video and other message content.
Chat Rooms (including private chat rooms, described below) are established on chat servers in advance of text conversations, and allow many users to communicate via messages. Any user may elect to join a chat room (become a participant), subject to prior subscription or registration procedures imposed by the on-line service provider or operator of the chat server(s). Many versions of chat client software, with varying functionality and communications protocols, are widely available on the Internet for download. Participants in a chat room receive all messages sent to the chat room and can decide to contribute input messages according to personal preference.
Private chat rooms are set up by a participant seeking to have private text communications with a selected one or more other participants in an existing chat. Toward this end, the initiating participant typically sends a "query" or similar message to another participant with whom the initiating participant wishes to privately communicate. A recipient of this query agrees to take part in a private chat with the initiating user by responding to the message. Others may be added in similar fashion. The server provides a separate chat room or channel not accessible by anyone not invited by those in the established private chat room.
Instant Messaging (IM) allows a user to launch a message to another user. Variants of IM permit a notice to be sent to others (e.g., those on a "buddy list" ) when a particular user logs on to a server, even without joining a chat or other two-or-more-person conversation. Users announce their availability to receive messages by electing options or submitting system parameters in advance. The sender of an instant message determines who will receive the message.
While the foregoing and other features of e-mail, chat and instant messaging have proven very useful in a number of contexts, these systems suffer from a number of real time limitations. For example, current chat environments limit users to participation in only one multiple-party (three or more participant) real-time chat room at a time. Users may participate in more than one conversation in real time, if these are two-way conversations. Likewise, a user may pursue multiple conversations (strings of messages) with multiple users, but only over an elapsed time period using multiple windows for conversation events, participation, and display.